package cn.review.han;

import java.util.Scanner;

//本类用于求圆形的面积
public class TestCircleArea {
    public static void main(String[] args) {
//        double r = 5.5;

        double r ;
        Scanner scanner = new Scanner(System.in);
        r= scanner.nextDouble();
        System.out.println(3.14*r*r);
        double r1 = new Scanner(System.in).nextDouble();
        System.out.println(3.14*Math.pow(r,2));
    }

}
